Prospective memory assessment in acute mild traumatic brain injury.

Prospective memory (PM) is the ability to remember to perform an intention at the appropriate time in the future. It is of primary importance for daily living, and its disruption may impact functional autonomy. To date, few studies have examined PM during the acute phase of mild traumatic brain injury (mTBI), despite the high prevalence of this neurological condition and its potential impact on cognition. Twenty mTBI patients (time since injury ranged from 45 to 73 days) and 15 healthy control participants performed the Ecological Test of Prospective Memory (TEMP), a simulated errand task in which participants were required to execute 10 event-based (EB) and five time-based (TB) tasks. The TEMP separately evaluates PM phases as well as prospective and retrospective components in event- and time-based conditions. Participants also completed a neuropsychological test battery. Correlations were performed between cognitive composite scores and the TEMP. mTBI patients experienced difficulty in learning the content of intentions, retrieving these intentions in the time-based condition (prospective component) and recalling the associated actions in the event- and time-based conditions (retrospective component). Retrospective memory composite score was correlated with the learning and retention phases of the TEMP, whereas attention/working memory and executive composite scores were correlated with the time-based condition and performance on the ongoing task. These results suggest the presence of global PM impairment during the acute phase of mTBI, as well as impairment of retrospective memory, attention/working memory, and executive functions, which are key components for PM performance.